Services provided by APs in a Wireless Local Area Network (WLAN) may be identified by one or more Extended Service Set Identifier (ESSID), and multiple APs may use the same ESSID, as shown in FIG. 1, the network adopting the same ESSID is an Extended Service Set (ESS), and all the APs in the same ESS are differentiated by Basic Service Set Identifiers (BSS ID), wherein one BSS ID corresponds to one AP, and the network adopting the same BSS ID is a Basic Service Set (BSS).
The procedure of each STA accessing an AP in the prior art mainly includes: by the STA, scanning at least one AP first where the scanned at least one AP is available for the STA to access, selecting an AP from the scanned at least one AP according to a predefined strategy, and sending an access request to the selected AP. For instance, the STA may select, from the scanned at least one AP, the one with the strongest signal intensity to which an access request is to be sent, and after receiving an access request from an STA, the AP allows the STA to access if the AP's load does not reach a load upper limit, and otherwise, rejects the STA from accessing.